Humidity control



Aug. 12, 1930. c. E. LEWIS HUMIDITY CONTROL Filed May 31, 1928 Patented Aug. 12, 1930 UNITED STATES PATENT OFFICE CARROLL E. LEWIS, OF ST. PAUL, MINNESOTA, ASSIGNOB TO THE LEWIS CORPORATION, INCL, OF MINNEAPOLIS, MINNESOTA, A. CORPORATION OF NEW MEXICO HUMIDITY CONTROL Application filed May 31,

This invention relates to humidity regulating systems and especially to mechanism.

for controlling the supply of moisture to the air within a room or building.

It is an object of my invention to provide a comparatively simple but highly efiicient humidity control or regulating mechanism which is highly sensitive in nature and which will maintain the air within a room or build ing at a desired humidity.

Another object is to provide a humidity control mechanism for regulating the supply of water or moisture to a humidifying device which will respond quickly to variations of humidity within a room or building and which will react immediately on an electro-magnetic valve controlling the flow of water or moisture to a humidifying device.

More specifically it is an object of my invention to provide a humidity control mechanism, wherein a suitable absorbent member variable in length according to the amount of moisture carried thereby is combined with extremely sensitive mechanism for instantly controlling by electricity the opening and closing of a valve.

A further object is to provide a. humidity regulator wherein electro-motive forces of high voltage may be employed to control a water supply valve and wherein the circuit control will be such that the device will function accurately after long continuous usage and will be free from fire hazard.

These and other objects and advantages of the invention will be apparent from the following description made in connection with the accompanying drawings wherein like reference characters refer to similar parts throughout the several views and in which:

Fig. l is a front elevation of the humidity controlled switch of my controlling mecha-.

nism;

Fig. 2 is a side elevation of the same;

Fig. 3 is a top plan view;

Fig. 4 is a cross section taken on the line 44 of Fig. 3;

Fig. 5 is a vertical section taken on the line 5-5 of Fig. 3, showing the fulcrum for the control lever and the means for retaining the 1928. Serial No. 281,722.

fulcrumed end of said lever against lateral displacement;

Fig. 6 is a side elevation with some parts broken away and others shown in section of the electromagnetic water supply valve of my humidity controlling mechanism; and

Fig. 7 is an electrical diagram of the circuit through the electro-magnetic valve and mercury switch.

As shown in the drawings, I provide a highly sensitive controller, the elements of which are mounted on a suitable plate or bracket, said controller including a special switch for opening or closing a circuit through an electro-magnetic coil which, as shown, operates a valve. The bracket or plate on which the control unit is mounted is adapted to be secured to a wall or other suitable supporting surface,and as shown, comprises a vertical plate 8 having a substantially fiat body portion, an inturned horizontally extending tongue 8 at its lower end and a pair of spaced inturned and horizontally extending arms 8 and 8 respectively at its upper end. Tongue 8 and arms 8 and 8 may be, as illustrated, constructed integrally with the body of plate 8 or may be rigidly secured with said plate in any suitable manner. If plate 8 is constructed of metal, as shown in the drawings, an insulating block 9 is preferably aflixed to the back thereof, said block having a longitudinall extending recess 9 extending therethroug the purpose of which will be later described. The horizontally projecting arm 8 is pr0- vided with an elongated horizontal slot 8" extending from its free end to a point spaced some distance from the body of plate 8. The arm 8 has a lower edge constituting a pair of spaced knife ed es F on which a very sensitive control lever, designated as an entirety by the letter L is adapted to fulcrumJ Control lever L is of special construction and of the bell crank order, comprising a substantially flat relativel short, horizontally extending arm 10, the rec end of which is disposed within the slot 8 of projecting arm 8, the width of said slot being sufiicient to allow the necessary movement of the lever arm 10 on fulcrum F-F. 1

iii

The "fulcrum end of lever arm is retained against lateral displacement by means of a hook shaped plate 11 secured to the end of projecting arm 8 and having an upwardly extending pointed extremity ll engaging the under side of lever arm 10 and seated in a corrugation 10 of said lever arm, which serves not only to retain the arm in proper position, but to moreover strengthen said arm. integrally formed with or rigidly secured to the lever arm 10 is an outwardly and downwardly projecting elongated lever arm 12 which is housed within the recess 9 of the insulating plate 9 extending the full height of said insulating plate and projecting from the lower end thereof and provided with a bifurcated lower extremity 12.

A vertically disposed channel guide 13 having a back provided with suitable perforations 13 and having inturned longitudinal front flanges 13 is rigidly supported in spaced relation to plate 8 by any suitable means, such as the horizontally projecting lugs 14- which may be rigidly connected at their inner ends with the front surface of plate 8. An elongated rectangular bar 15 constructed of some suitable absorbent material, which will expand when subjected to moisture is disposed in the guide channel 13 having its lower end adjustably supported or fixed by suitable means, such as the thumb screw 16 which may have threaded engagement with a horizontally projecting arm or lug 17 rigidly connected with the front ofplate 8 and carrying the threaded boss 17 at its outer extremity. As shown, expansible element 15 is vertically alined with the arm 10 of lever L and carries an upwardly projecting central stud 15 at its upper end which is seated in a suitable recess formed in a depending boss 10 of arm 10. Lever arm 10 is yieldingly held in contact with stud 15 by means of a coiled spring 18 fixed at its upper end to the free end of arm 10 and adjustably anchored at its lower end by means of a vertical thumb screw 19, said thumb screw being swiveled in the end of a suitable lug 20 rigidly connected with plate 8 or integrally formed therewith, said thumb screw having threaded engagement at its upper end with an internally threaded sleeve 21 to which the lower end of coil spring 18 is secured. Threaded sleeve 21 rigidly carries a bifurcated inward ly projecting arm 21 which slidably engages a vertically extending plate 22 rigidly fixed to the plate 8, the purpose of said plate and bifurcated arm being to prevent rotation of the sleeve 21 while permitting vertical adjustment thereof. A metal plate 15 is preferably interposed between the upper end of thumb screw 16 and the base of expansible member 15.

A special mercury switch is pivotally supported from the lower end of plate 8, as

shown, said switch comprising a sealed glass capsule 23, said capsule having therein a relatively small quantity of mercury M and being provided with a pair of spaced electrical contacts 2 1 through the bottom thereof, said contacts projecting a slight distance in the interior of capsule Glass capsule 23 may be mounted in a suitable bifurcated clamping member 25 engaging the medial portion of capsule 23 and having its upper end pivotally mounted between a pair of depending lugs 26 rigidly connected with the horizontally extending tongue 8 of the plate 8.

Contacts 24 are each connected to a terminal 27 which terminals may be conveniently mounted in the lower portion of the insulating blocl; 9. As shown, small sleeves 9* of insulating material project through the plate 8 from block 9 wherein terminals 27 are housed. The rear ends of terminals 27 may be electrically connected with an electromagnetic coil or solenoid 28, said coil, as illustrated, being adapted to operate a valve rod 29. The solenoid valve, as illustrated, is adapted to control the llow of water to any satisfactory humidiiying device, such as the humidifier illustrated in my pending application entitled Humidifier and heater, S. N. 261,576, filed March 14th, 1928. As shown, the valve casing has an intake passage 30 disposed above the tapered seat for the pointed valve rod or plunger 29 and a discharge passage 30" below said scat communicating with a suitable conduit 81 connected with the humiditying device. The passage of water through the valve, therefore, has a tendency to hold the valve rod in closed position against its seat rather than to unseat the valve member. Gravity normally holds the valve plunger 29 in closed position, while the electro-magnetic coil is operative to clevate the plunger to open the valve.

Operation As illustrated, the expansible element 15 is of some suitable absorbent material, such as an elongated block of wood with the grain running laterally of the block and thus being capable of expansion with the increase of moisture to which it is subjected. Being securely anchored at its lower end, its upper end will be moved vertically by expansion or contraction. The guide 13 for said expansible block is widely perforated at its rear side and open at its front side to permit the block to be subjected to the moisture of the air.

As shown in the drawings, the absorbent block 15 is relatively contracted with the mercury capsule 23 declined slightly from left to right. Since contacts 2% are disposed in the right end of said mercury capsule the circuit through electro-maguetic coil 28 is closed with the capsule in said postion. Valve plunger 29 is elevated by electro-magnetic force and water may flow through the valve into the humidifying device.

Upon expansion of block 15, the short lever arm 10 is swung slightly in an upward direction against the tension of coil spring 18 and fulcrums on the knife edges F. Arm 10 is prevented from lateral dis lacement by means of its engagement wit the pointed extremity of the hook shaped plate 11. The movement of said arm will, of course, be very slight due to the fact that the expansion of absorbent block 11 is necessarily small and its free end, as shown in Fig. 2, works through the slot 8 in the projecting arm 8 of plate 8. The elongated arm 12 of lever L, of course, swings with arm 10, working in the recess 9' of the insulating block and its lower extremity 12 is moved through a considerable distance. The bifurcated end 12 of the lever arm 12 being eccentrically connected with the pivoted glass capsule by means of a suitable pin 25 causes said capsule to swing from the declined position shown in Fig. 1 to the oppositely declined position shown in dotted lines in Fig. 7. The instant the capsule 23 is swung past the horizontal position the mercury M by gravity will run to the opposite end of the capsule leaving contacts 24 uncovered. This, of course, breaks the circuit through the electro-magnetic coil and the weight of the plunger valve 29 is sufficient to cause the same to drop into its tapered seat, closing the valve.

As soon as the humidity of the air surrounding expansible block 15 is lowered to a predetermined degree the contraction of the block 15 due thereto causes the control lever to move from right to left reversing the op eration above described and returning the mercury ca sule to the position shown in Fig. 1, there y again causing the circuit to be closed by the mercury in the capsule.

A very fine adjustment may be made to set the device for a desired humidity by regulating the thumb screw 16, which supports and anchors the lower end of the ex ansible block 15. Furtheradjustment may e made to some extent by varying the tension of spring 18 through thumb screw 19, although t e purpose of the coil spring is preferably to exert only suflicient tension to keep the boss 10 of lever arm 10 in contact with the stud 15 at the upper end of the expansible block. The mercury switch for controlling the circuit through the solenoid is preferable for several reasons. It is absolutely reliable to make or break the circuit and there is no possibility for oxidation or corrosion within the capsule. clean and instantaneous in operation and if the capsule is filled with inert gases the are is instantly stifled when contact is made, thereby eliminating fire hazard.

With my control mechanism it will be seen that although the expansible member has an The contact is, permanently member will react on the shorter end of lever L, causing the elongated end 12 thereof at its lower extremity to swing through a considerable arc, the fulcrumed extremity of arm 12 being eccentrically connected with the mounting for capsule 23 and connected to the left of the pivot for said capsule as illustrated in Fig. 1. This insures the swinging of said capsule. The tipping of the mercury capsule 23 from one side to another requires only a very slight movement and an extremely small vertical movement of expansible block 15 will move the elongated arm 12 of the lever L through the requisite distance. Gravity causes the heavy mercury tolgreatly facilitate the tilting of the capsu c.

It is, of course, desirable to use electromotive forces of comparatively high voltage for operating the solenoid valve and if mercury capsule 23 is filled-with inert gases the arc is immediately stifled when contact is broken by the members 24. The construction of said mercury switch also prevents corrosion or injury to the contacts 2 which would otherwise make my device inaccurate within a short time. From the foregoing description it will be seen that I have invented a simple, highly efiicient control for a plication to humidity regulators, capable of eing easily and quickly installed in connection with humidifying devices and adapted to be easily adjusted.

It will, of course, be understood that various changes may be made in the form, details, arrangement and proportions of the parts without departing from the scope of ap plicants invention.

What is claimed is:

1. Humidit controlling mechanism comprising an a sorbent element rectilinearly expansible or contractible with variations in the humidity of the air to which it is exposed, means for anchoring one end of said element, the opposite end being movable with said humidity variations, a bell crank lever having a relatively short arm and a relatively long arm, said short arm being fulcrumed adjacent its outer end and having its intermediate portion yieldingly held in contact with the movable end of said expansible element, an oscillatory switch connected with the outer end of said longer arm, and adapted to be tilted by the movement of said arm to make or break an electric circuit.

2. Humidity controlling mechanism comprising a support, an absorbent element rectilinearly expansible or contractible with variations in the humidity of the air to which it is exposed, means for anchoring one end of said element, the opposite end being movable with said humidity variations, a bell crank lever having a relatively short arm disposed above the movable end of said variable element, a fulcrum for said lever mounted on said support, means for yieldingly holding the short arm of said lever against abutment means carried by the movable end of said variable element, an electric switch for controlling the operation of a humiditying device. said bell c'ank lever having a relatively long arm extending from said shorter w arm and an eccentric connection between said switch and the longer arm of said lever.

3. In humidity controlling mechanism, a support, an elongated hydrostatic element mounted on said support having one of its ends relatively fixed and its opposite end relatively movable, a bell crank lever having a fulcrum on said support adjacent one end of said hydrostatic element, said bell cranlr having a short arm extending transversely of the no movable end of said hydrostatic element and having a relatively long arm extending substantially longitudinally of said hydrostatic element, an oscillatory electrical switch piv' oted adjacent the free end of said long arm and an eccentric connection between said free end and said switch.

at. In humidity controlling mechanism, an elongated support, adapted to be mounted substantially vertically. an elongated hydro- 30 static element mounted longitudinally of said support and having its lower end relatively fixed and its upper end relatively movable, a bell crank lever tulcrumed on said support and having a relatively short arm disposed transversely above the movable end of said hydrostatic element and re-acted on thereby and having an elongated arm extending longitudinally of said hydrostatic element to a point adjacent the lower end of said sup 40 port, guide means on said support for holding said hydrostatic element and an oscillatory electric switch pivoted on the lower portion of said support adjacent the free end of said elongated arm and an eccentric connec- 45 tion between said switch and said free end of said arm.

In testimony whereof I afiizr my signature.

CARROLL E. LEWIS. 

